Pre-Installation Checklist — Mysa for In-Floor Heating

Last updated: May 26, 2026

Before You Start

Complete this checklist before you begin any installation work. It takes 10 minutes and prevents costly mistakes.

Step 1: Verify Your Circuit Voltage

What you need: A voltmeter (available at hardware stores for $10–$20)

Check Your Breaker Type

Look at your electrical panel and find the breaker controlling your floor heating circuit:

Single-pole breaker (narrow, one switch) = 120V circuit
Double-pole breaker (wider, two switches connected) = 240V circuit

Confirm with a Voltmeter

Turn off the breaker
Set your voltmeter to AC voltage
Turn the breaker back on
Carefully touch the voltmeter probes to the breaker terminals (or ask an electrician to do this)

Expected readings:

Single-pole breaker: ~120V
Double-pole breaker: ~240V

Important: If your voltmeter reading doesn't match your breaker type, consult a licensed electrician before proceeding.

Step 2: Verify Wattage Requirements

Your floor heating system has a wattage rating. Mysa for In-Floor Heating has maximum load limits:

Check Your Heating System

Find your floor heating system's wattage (on the mat, documentation, or manufacturer specs)
Write down the wattage: __________ W
Verify it's under the max for your voltage:
- 120V system? Must be ≤ 1,900W
- 240V system? Must be ≤ 3,800W

If your system exceeds these limits: Mysa cannot safely control it. Contact your heating system manufacturer or a licensed electrician for alternatives.

Step 3: Check System Compatibility

Mysa for In-Floor Heating works with electric heating systems only. Verify your system type:

Compatible Systems ✓

Electric in-floor heating mats
Under-tile heating systems
Electric heating cables
Radiant floor heating (electric)

Incompatible Systems ✗

Hydronic (hot water) in-floor systems
24V heating systems
Forced air systems
Heat pumps
Natural gas or oil heating systems

Important: If you have a hydronic (hot water) in-floor system, Mysa for In-Floor Heating will not work. These systems require different controls.

Step 4: Confirm Floor Sensor Location

Before installation, decide where your floor temperature sensor will go:

Sensor location planned: Choose a spot within 15 feet (4.5 meters) of your thermostat in the heated area
Protected placement: Ensure the sensor won't be damaged by foot traffic, furniture, or water
Good sensor location examples:
- Under a floor tile or mat (covered, protected)
- In a small conduit tube under the floor
- Taped to the top of the heating mat in an inconspicuous area
- Ask your floor heating manufacturer for their recommendation

Note: The included floor sensor is 15 feet long and works with 5K–40K Ohm resistance sensors. If you need a longer sensor, compatible sensors are available separately.

Step 5: Turn Off the Breaker

Before touching any wires:

Locate the breaker controlling your floor heating circuit
Switch it to OFF
Leave it off during the entire installation

Test for Power

Use a non-contact voltage detector (a pen-sized safety tool, ~$15):

Turn on your non-contact voltage detector
Touch it near the circuit wires at your wall box
It should not beep or light up
If it does, power is still on — call a licensed electrician

Step 6: Verify You're NOT on a GFCI Circuit

Important: Mysa for In-Floor Heating has a built-in Class A GFCI that cannot be disabled. Installing it on an existing GFCI-protected circuit will cause false trips and prevent operation.

Check for These:

Your breaker is not labeled "GFCI"
Your breaker is not labeled "GFI"
There is no GFCI outlet (outlet with Test/Reset buttons) on this circuit
You've confirmed with a licensed electrician (if unsure)

Why This Matters

If you install Mysa for In-Floor Heating on a GFCI-protected circuit:

The built-in GFCI will constantly trip
Your floor heater won't run
You won't be able to use the system

Solution: If your current circuit is GFCI-protected, have an electrician install a new non-GFCI circuit for your floor heating system.

Step 7: Gather Your Tools

Before installation, make sure you have:

Voltmeter — to verify circuit voltage
Non-contact voltage detector — to test for power
Screwdrivers — flat and Phillips head
Wire strippers — to expose about 3/4 inch of copper wire
Wire nuts — 4 included in the Mysa box
Needle-nose pliers — to insert wires into terminals
Flashlight — to see inside the wall box
Thermometer (optional) — to verify your floor sensor works after installation

Important: Mysa for In-Floor Heating requires copper wiring only. Aluminum wiring is not compatible.

Step 8: Verify Your Wall Box

Your thermostat must fit in a standard electrical box:

You have access to an empty wall box (or someone to install one)
The wall box is in a location convenient for temperature control
The wall box is not in a humid area (bathroom walls, near windows)
The wall box is away from direct sunlight

Step 9: Check Wi-Fi Requirements

Mysa for In-Floor Heating connects to your home Wi-Fi network:

2.4 GHz Wi-Fi available — Mysa does not work with 5 GHz-only networks
Wi-Fi signal reaches installation location — test with your phone
Mysa app downloaded — available for iOS and Android

Tip: If your router broadcasts both 2.4 GHz and 5 GHz, you can use the same network name. Mysa will automatically connect to the 2.4 GHz band.

Installation Readiness Checklist

Before calling an electrician or starting installation:

Voltage verified (120V or 240V)
Wattage confirmed (under max limits)
System compatibility confirmed (electric heating only)
Breaker switched off
Power confirmed off (tested with voltage detector)
GFCI circuit ruled out
Floor sensor location planned
Tools gathered (including wire nuts)
Copper wiring verified
Wall box ready
2.4 GHz Wi-Fi confirmed

Next Steps

Ready to install?

Review our Wiring Reference Guide for terminal connections
Follow the detailed installation instructions that came with your Mysa for In-Floor Heating

Not sure about the wiring?

See DIY vs Professional Installation to decide if you should hire an electrician
Share the Wiring Reference Guide with your electrician

Need Help?

If you encounter any issues during this checklist or have questions about your electrical setup:

Email: install@getmysa.com

Our team can help you verify your setup or recommend a qualified electrician in your area.